Cryptic transmission of SARS-CoV-2 and the first COVID-19 wave

Article

关键词: EPIDEMIC;    DYNAMICS;    SPREAD;    EUROPE;   

DOI  :  10.1038/s41586-021-04130-w

来源: SCIE

【 摘 要 】

Considerable uncertainty surrounds the timeline of introductions and onsets of local transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) globally(1-7). Although a limited number of SARS-CoV-2 introductions were reported in January and February 2020 (refs.(8,9)), the narrowness of the initial testing criteria, combined with a slow growth in testing capacity and porous travel screening(10), left many countries vulnerable to unmitigated, cryptic transmission. Here we use a global metapopulation epidemic model to provide a mechanistic understanding of the early dispersal of infections and the temporal windows of the introduction of SARS-CoV-2 and onset of local transmission in Europe and the USA. We find that community transmission of SARS-CoV-2 was likely to have been present in several areas of Europe and the USA by January 2020, and estimate that by early March, only 1 to 4 in 100 SARS-CoV-2 infections were detected by surveillance systems. The modelling results highlight international travel as the key driver of the introduction of SARS-CoV-2, with possible introductions and transmission events as early as December 2019 to January 2020. We find a heterogeneous geographic distribution of cumulative infection attack rates by 4 July 2020, ranging from 0.78% to 15.2% across US states and 0.19% to 13.2% in European countries. Our approach complements phylogenetic analyses and other surveillance approaches and provides insights that can be used to design innovative, model-driven surveillance systems that guide enhanced testing and response strategies.

【 授权许可】

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